共查询到16条相似文献,搜索用时 109 毫秒
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一种快速去块滤波器结构 总被引:1,自引:0,他引:1
为了消除由于图象的预测,补偿,变换,量化引起得块效应,H.264/AVC标准中引入了去块滤波器.本文通过采用并行滤波,介绍了一种编解码环中快速实现去块滤波的滤波器结构,分析了该结构的滤波原理以及滤波过程中数据的存储. 相似文献
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H.265继续沿用H.264编码架构,去方块滤波器也是H.265视频编码标准的一个重要选项,去除混合编码带来的块效应极大改善了视频的质量,但由于H.265超级宏块的存在,去方块效应滤波相关参数层层嵌入在每个小的处理单元中,这种结构不利于实现基于宏块行间的并行化,同时也很难高效地利用Cortex-A9架构SIMD优化性能.首先详细分析H.265标准去块滤波器的处理过程以及并行处理的困难,进而提出一种便于实现基于宏块行间的并行去块滤波结构,然后进行Cortex-A9汇编优化.基于HM14.0实验,改进去方块效应滤波器计算复杂度从占整个解码器25%降至14%,大大提升了解码器性能,为移动设备上实现H.265大分辨率视频实时播放奠定基础. 相似文献
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H.264去块滤波快速算法的设计与实现 总被引:1,自引:0,他引:1
介绍了H.264去块滤波的基本原理,并基于滤波强度预判的思想提出了一种快速去块滤波算法.通过软件实现验证了该算法在不影响解码图像质量的前提下较标准中的算法节省了约70%的滤波运算量,有效提高了软件解码器的运行速度,有助于H.264解码器实时应用的实现. 相似文献
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在此完成了H.264/AVC解码器中高效低功耗的去块效应滤波器设计.该设计采用5阶流水线技术,配合混合边界滤波顺序与打乱次序的存储数据更新机制,解决了数据与结构冒险问题,因此获得了正常流水线操作中的0延迟,使得基于流水线的设计架构得到最大程度的实现,同时提高了系统吞吐量并降低了功耗.该设计在FPGA芯片上验证的工作频率上限大约为200 MHz,吞吐量为滤波单个宏块需要198个时钟周期.使用0.18μmCMOS工艺,Synopsys Co.的DC工具对滤波器模块进行综合,结果为时序收敛,功耗约为2μW.仿真结果显示,可以对QCIF标准的视频(60 f/s)进行实时环路滤波,该环路滤波器可以用于H.264/Avc实时解码器中. 相似文献
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《Journal of Visual Communication and Image Representation》2014,25(5):1044-1055
Transform coding has been widely used in video coding standards, such as H.264 advanced video coding (H.264/AVC) and high efficiency video coding (HEVC). But the coded video sequences suffer from annoying coding artifacts, such as blocking and ringing artifacts. In this paper, we propose the quadtree-based non-local Kuan’s (QNLK) filter to suppress the quantization noise optimally and improve the objective and subjective quality of the reconstructed frame simultaneously. The proposed filter takes advantage of the non-local Kuan’s (NLK) filter to restore the quantized signal in transform domain. Restored coefficients are then projected onto designed quantization constraint sets (QCS). Quadtree-based signaling strategy is used at the end of QNLK for adaptive filtering on/off control. Experimental results of QNLK show that the proposed method achieves significant objective coding gain and visual quality improvement, compared with both H.264/AVC high profile and HEVC. 相似文献
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Seung-Ho Shin Kyu-Ho Park Young-Joon Chai Tae-Yong Kim 《Signal Processing: Image Communication》2010,25(4):255-267
H.264/AVC supports variable block motion compensation, multiple reference frames, 1/4-pixel motion vector accuracy, and in-loop deblocking filter, compared with previous video coding standards. While these coding techniques are major functions for video compression improvement, they lead to high computational complexity at the same time. For the H.264 video coding techniques to be actually applied on low-end/low-bit rates terminals more extensively, it is essential to improve the coding efficiency. Currently the H.264 deblocking filter, which can improve the subjective quality of video, is hardly used on low-end terminals due to computational complexity.In this paper, we propose an enhanced method of deblocking filter that efficiently reduces the blocking artifacts occurring during the low-bit rates video coding. In the ‘variable block-based deblocking filter (VBDF)’ proposed in this paper, the temporal and spatial characteristics of moving pictures are extracted using the variable block-size information of motion compensation, the filter mode is classified into four different modes according to the moving-picture characteristics, and the adaptive filtering is executed in the separate modes. The proposed VBDF can reduce the blocking artifacts, prevent excessive blurring effects, and achieve about 30–40% computational speedup at about the same PSNR compared with the existing methods. 相似文献
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This paper presents an improved redundant picture coding method that efficiently enhances the error resiliency of H.264. The proposed method applies polyphase downsampling to residual blocks obtained from inter prediction and selectively encodes the rearranged residual blocks in the redundant picture coding process. Moreover, a spatial‐temporal sample construction method is developed for the redundant coded picture, which further improves the reconstructed picture quality in error prone environments. Simulations based on JM11.0 were run to verify the proposed method on different test sequences in various error prone environments with average packet loss rates of 3%, 5%, 10%, and 20%. Results of the simulations show that the presented method significantly improves the robustness of H.264 to packet loss by 1.6 dB PSNR on average over the conventional redundant picture coding method. 相似文献
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基于Directshow的H.264流媒体播放器设计 总被引:1,自引:0,他引:1
基于目前最新的视频压缩编解码标准H.264,采用Directshow应用框架,设计了网络流媒体播放器系统;Directshow是微软提供的基于windows平台的优秀的流媒体应用架构,H.264标准具有高压缩比和优良的网络亲和性,基于Directshow和H.264设计的网络流媒体播放器不仅具有优良的系统架构,同时具有更好的灵活性和可扩展性,可以很方便地应用于视频点播系统(Video On Demand System)中和移植到嵌入式WINCE平台。基于Directshow分析和设计了网络源Filter和H.264解码Filter,同时阐述了网络流媒体播放器系统的整体框架。 相似文献